Design And Research Of The Construction Platform Of Steel Tubular With Couplers In Shallow Water

Recently, with the rapid development of electrical construction, a variety of line towers are in the ascendant. Owing to the wider distribution of hydrographic net, some of the line towers unavoidably locate in the water. In the past, while the towers are put up in shallow areas, construction organization usually adopted the method of building a temporary road and a soil cofferdam. However, the traditional working scheme not only has a huge quantity of earthwork, but also easily cause a larger damage of surrounding environment, especially in aquafarm such as fishpond, crab pond etc.. Therefore, for solving the construction problem of tower foundation, the economy as well as environmental trestle and construction platform made of conventional steel pipes has an important practical significance. Yet, because such trestle and construction platform is a temporary structure, which is different from the permanent ones, so its design is subjected to some factors, for instance, feasibility, water-level fluctuation, period, construction technology, economic benefits etc.. Accordingly, in order to ensure the engineering quality and project duration, the design and construction craft of the trestle and construction platform above water is necessary to be intensively studied so that it could create a good economic benefit.This thesis focuses on the design approaches of "steel-pipe trestle and construction platform" whose materials can be circularly used, and carries out relevant theoretical calculation and analysis depending on an appropriate project. This aims at forming a typical design and construction scheme, which can act as reference for the subsequent similar engineering. The main work is in the following.1) The specific layout form and structural measures of "steel-pipe trestle and construction platform" structure are studied by making clear many-sided contents, such as research background, selection principles, designed load, material requirements and so on, which should be also followed by the construction conditions and usage requirements.2) The "steel-pipe trestle and construction platform" structure is accepted the mechanical analysis and safety assessment that are done by MIDAS finite element software based on the field data, as well as the construction load (including the vibration load). Afterwards, the minimum buried depths of vertical rods are confirmed, and a feasible program for reinforcing is brought out according to the computed results.3) The critical geometric length of steel-pipe columns is determined with elastic and elastoplastic analytical method, respectively. Based on the computed results the application scope of "steel-pipe trestle and construction platform" structure is given. Furthermore, the overall stability of the structure and the accuracy of the safety factor values are verified through buckling analysis.4) The application process of "steel-pipe trestle and construction platform" is discussed when its technical and economic efficiency is analyzed. On the other hand, the settlement observation test is done while the corresponding tower foundation is constructed. The test results have demonstrated that the designed construction platform met the requirements of the design code and use.